Method of treating waste sulfite liquor and product produced thereby.



passing off therein,

fwood is then FFQ.

NEW YORK, ASSIGNOR TO HYDROLOSE PROCESS CORPORATION, A CORPORATION OF NEW YORK.

mn'rnon or 'rnua'rm'e No Drawing.

To all whom it may concern:

Be it known that l, WALTER K. FREEMAN, a citizen of the United States, residing at Oscawana, in the county of Westchester and State of New York, have invented certain new and useful Improvements in Methpds of Treating Waste Sufite Liquor and Products Produced Thereby; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to make and use the same. 7

My invention consists in a method of treating sulfite waste liquor, a waste product of the wood pulp mills, to convert said liquor into new and useful composi ions of matter, and the subsequent treatment of the compositions in various ways, or mixing them with various chemicals or substances to produce other new compositions of matter which may be used in the manufacture of a great variety of articles differing widely in their character and uses.

My invention also covers the product.

In-order to understand the principal ingredients of the sulfite waste liquor, and to appreciate the large percentage of wood it may be well to consider briefly the sulfite pulp process for the manufacture of paper, in the course of which this by-product results.

Sulfur is first burned and the gas given ofi is cooled and passed into a tower in which lime rock is distributed, then Water is caused to flow over the surface of the rock, dissolving part of the calcium and sulfur to form bisullite of lime solution having a percentage of free sulfurous acid. This liquid. 's I then brought into contact with wood chips placed in a closed digester and boiled under a pressure of about sixty pounds, for several. hours.

beaten and washed to free it from the chemicals, after which it is bleached, gathered and distributed to the calenders and formed into various kinds of paper. In practice, approximately 40% of the original weight of the dry wood is recovered for use in the manufacture of paper. The remaining 60% of the original dry wood, plus the chemicals, about 300 pounds of sulfu'r'and 200 pounds of lime per ton Specification of Letters Patent.

' It is apparent -'lhe softened WASTE SULFITE LIQUOR AND PRODUCT PRODUCED THEREBY.

of wood, pass off in the sulfite waste liquor. from this calculation that more than the value of the paper pulp as such, is lost in the art of making it. also apparent that only the stronger and more matured cellulose constituents can withstand this treatment without being dissolved, so that all of the original wood other than the matured cellulose is lost and goes It is' Patented Mar. Ml, 19165.

Application filed November 25, 1913. Serial No. 803,044.

off with the chemicals and water to make up this sulfite waste liquor. of the original wood consists of the primitive lignin-cellulose, the primitive and formative cells, protoplasm, resins and other secretions of the wood and such of the matured cells as have been dissolved in the process'of digestion. The yearly loss to paper manufacturers from this large percentage of wasted wood amounts to millions of dollars, and aside from this enormous loss, the sulfite waste liquor, on account of its offensive odor, has been a nuisance to manufacturers, and its poisonous and acrid ingredients cause such serious pollution of the streams into which it is emptied that it has become a subject of legislation in some States.

Certain of the chemical elements found present in this sulfite waste liquor, among which are the spent bi-sulfite of lime and the sulfurous acid, prevent the solids of the waste liquor from entering into combination with other chemicals to form any composition or compound useful for any purpose now knownl r a salt solution to effect coagulation of some of the ingredients of said liquor, and then add a suitable precipitant to convert the remaining sulfurous compounds, preferably to inert solids; after which the resulting substantially neutral syrup with or without the precipitates may be. bleached, evaporated down to an anhydrous mass, and ground into a powder. This powder may then be The lost part Y and the manner mixed with a suitable oxy-chlorid bond such as magnesium ox'id and chlorid or any other suitable oxy-chlorid bond, and ground therewith into a powder from which numerous fireproof and resistant articles of varying hardness and elasticity may be made, with or without other ingredients. 1

I have found in practice that the method of treating the sulfite liquor in accordance with my invention may be varied at difierent steps in the process, and that certain ingredients in the waste liquor may be recovered during the method of treating the same to obtain the compositions of. matter which form one of the objects of this invention; but in order to aid those skilled in the art in a thorough understanding of the invention be an eflicacious manner 'waste liquor for the purpose intended.

I first run the sulfite Waste liquor into an acid resisting tank, where the liquor is partially evaporated to increase its density so as to economize in the amount of chemicals with which the liquor is subsequently treated. I have found in practice that for the the liquor should first be evaporated down to about 20% to 30% of solids. The resulting liquor is-then run into a beater where it maybe partially cooled or cooled below 150 F., after which a sufiicient amount of a coagulating agent is added to I of the agent air or'mechanical lowed to stand for the chlorid throu the liquor. The object of allowing the syrup to partially cool before adding-the coagulating'agent' is to prevent the vaporization of a considerable portion of the volatile elements which would occur if the temperature were kept too high. In practice, I have found that an active sodium salt, and preferably sodium chlorid, is very satisfactory, but any halogen salt of an alkali base may be used. The hot semi-solid or syrupy liquor is then beaten while the temperature is maintained at approximately 200 Fahr. until there are indications of coagulation of the solids from the water element. The salt, under these conditions, apparently effects the coagulation or curdling of some of the components of the liquor, as it is well known that salt or sodiumchlorid is markedly effective in coagulating some albuminoids.

he syrupy substance s then drawn into 'a settling tank preferably provided with an agitator, where it'is alseveral hours until separation is evidenced, and when at a temperature of about 100 Fahn, a small percentage of a suitable precipitant, such as a chlorid of the alkali earth metal group, and preferably barium chlorid, is added and the mixture agitated for a sufficient length of time to thoroughly intermix and distribute gh the mass so as to bring it into intimate contact with the sulfur, calof practising the same, I will set forth in detail what I have found to of treating the of the syrup, effects satisfactory and eflicient precipitation where the syrup has been treated with the salt but the barium chlorid crystals may be introduced without dissolving them. The addition of barium chlorid at this stage seems to accelerate gathering or aggregation of the coagulated portions into larger masses When it is desired to separate the wood derivatives or constituents from the precipitatesthus formed, the entire mixture, including the precipitates, is run into a comparatively deep settling tank where the precipitates are allowed to settle and the syrupy part of the mixture containing the wood derivatives is then drawn off. The drawn off 'liquor is practically black, and hence any derived product would not be suitable for the manufacture of light colored articles without first bleaching the composition to remove the coloring matter doing this I preferably cool the syrup down to approximately normal temperature and bleach the same by any suitable process such as the electrolytic ozone process or by chlorin gas, or by direct electrolytic action, during which step further precipitates are formed, and a furfural scum rises, all of which may be separated from the liquor, leaving a fluid of lighter color, the shade or tone of which may be governedby the degree of bleaching.

After bleaching the composition, if bleaching is desired, I run the bleached syrup composition together with the precipitates into an evaporating chamber preferably provided with a vacuum arrangement to facilitate drying at a lower temperature, and in this chamber I evaporate the composition down to approximately 80 to 90 per cent. of solids. The resulting composition is a brittle mass whichmay then be reduced to powder and shipped in suitable containers. F or the sake of convenience I shall designate the syrup and the precipitates together whether they be in liquid .or solid condition xylium.

After precipitation has taken place as above set forth, the syrupy mass which is drawn ofi or separated from the precipitates, contains the Wood derivatives recovered from the former sulfite waste liquor, which derivatives consist of the primitive ligninrcellulose, the primitive and formative .cells, and resins and other secretions of the therefrom. In 7 may wood and such of the matured cells as have been dissolved in the process of digestion. For the sake-of convenience, in referring to this new composition of matter withoutthe precipitates, I will designate the same as xylozo. The term 'is to designate this new composition of matter in any form, whether in the syrupy semi-solid state, bleached or unbleached, or after being evaporated down to an anhydrous mass and reduced to powder.

The inert precipitate or solids from which the syrupy mass is drawn off or separated, contains the neutralized spent chemical compounds of the sulfite waste liquor such as the sulfur calcium compounds, and this precipitate may be ground up and used'with suitable mixtures for roofing and other purposes. To this precipitate I apply the term xylosca. I

If the anhydrous mass is to be used in the manufacture of large articles or in coarser work, the syrupy substance need not be allowed to stand to facilitate precipitation, since the chemical compounds distributed through the liquor need only be reduced to inert substances, in which case the entire syrupy mixture, may be evaporated down to an anhydrous mass after or without bleaching. The three words, xylium, xylozo and xylosca are derivatives of the Greek word xylon meaning wood, and I believe them to be appropriate terms by which'the new compositions of matter may be designated; the first others species under the genus.

If desired, the powdered anhydrous composition xylium may be mixed with suitable proportions of a suitable dry metallic oxid such as dry magnesium oxid, and the two reduced to a powdered form, or the anhydrous powdered composition may be mixed with a suitable amount of a dry metallic oxid and chlorid such as magnesium oxid and chlorid and ground up to form a powder. Other oxy-chlorids such for instance as zinc, barium, aluminum or platinum. oxids anld' chlorids, may be substituted for the magnesium oxid and chlorid. This powder may be used alone or with other ingredients, and when moistened with water be used to. form various fireproof and moisture-proof 'articles of varying hardness and elasticity. The powder should be kept in air-tight containers.

It is immaterial ,to my broad invention whether the recovered by-product xylium ishroken up and ground together with the metal oxid alone having a suitable amount of a ('hlol'ld solution added at the time that the powder is to be used, or whether it is broken up and ground with the oxid and chlorid in one operation to form the resulting powder. The oxy-chlorid bond and the resultingcomposition may be mixed in any suitable manbeing the genus and thener so long as the three ingredients are brought into intimate contact to bring about the proper chemical action to perform the desired result.

In practice, I have found that it is preferable to reducethe anhydrous mass to a fine powder, and then thoroughly mix this powder with a substantially equal part by weight of dry powdered magnesium oxid and a half part by weight of dry powdered magnesium chlorid to form the resulting composition. ingredients in practice, and whether the metal chlorid is to be ground in with the metal oxid or added later as a chlorid solution, will depend entirely upon'the facilities and convenience to the manufacturer.

The xylosca or xylozo oxy-chlorid powder may be mixed in a suitable manner with fibrous material and other ingredients properly treated, from which mixture plasterboards, etc., may be made. These boards are practically fireproof and moisture-proof and have the desired degree of elasticity to receive and hold nails and to withstand various uses. The xylosca or xylozo oxychlorid powder may likewise be mixed with different ingredients and suitably treated to form a flooring composition which is fireproof, less affected by moisture than the well known plastic cement, and which has a degree of elasticity which will permit it to be cut or drilled without cracking, which makes it more suitable for flooring.

I have found in practice thatthe xylium' powder, by being suitably treated by different processes, may be used in the manufacture of .molded articles," such as billiard balls,'lasts on which rubbers may be vulcanized-, insulating articles for electrical apparatus, or for picture-frames and fresco work; and it is better suited for the manufacture of these articles than'anything now on the market for such purposes. I have also found this powder useful in making a composition drates convertible into alcohol, and by adding a suitable fermenting agent, to the neu-. tral partially evaporated sulfite waste liquor and allowing it to stand, fermentation will take place, after which the alcohol may be distilled off from the syrupy liquor and recovered. About nineteen gallons of alco hol per ton may be recovered at a cost of about twenty-two cents per gallon, without affecting the character of the remaining syrupy liquor so far as concerns its subse- The method of mixing theseuseful as lithographers stone, and which has valuable qualities as such. I

quent method of treating or the resulting 6 per cent. tannic acid present in the sul-' fite waste liquor, and when the waste liquor is' neutralized and evaporated to syrupy xylium, the tannic acid remains in the mixture, and I have found in practice that the xylium may be, used for tanning leather, and that leather tanned with this substance is of a peculiarly fine quality.

The syrupy xylozo, containing as it does, the primitive lignin-cellulose resins, oils, and primitive cells, when bleached may be used in the manufacture] of soap. I have found in practice thata very fine quality of soap may be easily and very economically made from this syrupy xylozo. also found that the syrupy xylozo may be readily treated to form a compound which may be used as an ingredient in making water colors which have .the character of retaining their color in a measure unknown in any of the colors now on the market.

Having this disclosure of my broad invention for the recovery ofthe wood derivatives and chemical constituents of the sulfite waste liquor of wood pulp mills, changes in the method of recovery and substitutions in the ingredients used may suggest themselves to those skilled in the art, and while I have described one particular process of manufacturing wood pulp in the carrying out of Which sulfite waste liquor results, it is obvious that my broad invention is not to be limited to the treatment of the sulfite waste liquor resulting from any particular process.

Having thus described my invention,what I claim as new and desire to secure by Letters Patent, isz.

'1'. The method of treating sulfite waste liquor which consists in' partially evaporating said liquor, treating said liquor with a reagent consisting'in part atleast of a halogen salt of an alkali metal and subsequentlyprecipitating from out of the liquor substances affected by's'aid reagent.

2. The method of treating sulfite waste liquor from wood pulp mills, which consists in partially evaporating said liquor, treating with a chlorid of an alkali metal said waste liquor and then treating said liquor with barium chlorid to cause precipitation of the sulfur calcium compounds in said liquor as solids.

3. The. method of treating sulfite waste liquor from wood pulp mills, which consists in partially evaporating said liquor, adding increase its density,

I have to said liquor sodium chlorid to assist in 00- agulating the same, and then bringing barium chlorid into contact with the constituents of said resulting liquor to form precipitates. x I 4. The method of treating sulfite waste liquor from wood pulp mills, which consists in heating said liquor'to concentrate it, adding thereto a chlorid of an alkali metal, agitating, then adding a chlorid of the alkaliearth metal group and agitating to bring the said chlorid into contact with the spent chemical compounds in said liquor to form substantially neutral inert substances;

5. The method of treating sulfite waste liquor from wood pulp mills, which consists in partially evaporating said waste liquor to adding a suitable alkaline halogen salt to substantially neutralize the resulting syrup and agitatingthe same while keeping hot, allowing the syrup to partially cool and then adding a chlorid of the alkali-earth metal group and bringing thesame into contact with the syrup to form precipitates.

6. The method of treating sulfite waste liquor from wood pulpmills, which consists in heating the waste liquor to concentrate it and then adding sodium chlorid and agitating the mixture while keeping hot, allowing the mixture to cool to less than 150 Fahn, and then adding barium chlorid as a precipitant agent and bringing the sameinto intimate contact with the said mixture to form insoluble solids thereof as precipitates.

7. The method of treating hot sulfite waste 8. The method'of treating sulfite wasteliquor from wood pulp mills, which consists in heating said liquor and adding thereto a chlorid of an alkali metal and beating until separation is evidenced, and then adding a suitable chlorid of the alkali earth metal group to elfect separation of the wood de-.

rivatives in the mixture. v

9. The method of treating sulfite waste liquor from wood pulp mills, which consists in heating said liquor to concentrate it and adding thereto a haloid of an alkali metal and beating until separation is evidenced, allowing the mixture to settle for several hours, adding a suitable haloid of the alkali earth metal group and agitating to bring the same in contact-with the mixture to ef-v fect precipitation.

10. The method of treating sulfite waste Fahr.,'and then adding a small liquor from wood pulp mills, which consists in partially evaporating said liquor and adding thereto a haloid of an alkali metal and beating until separation is evidenced, and then adding a suitable chlorid of the alkali earth metal group and agitating to effect separation of the lignin-cellulose constituents from the spent bisulfite ingredients of said liquor.

11. The method of treating sulfite waste liquor from wood pulp mills, which consists in partially evaporating said waste liquor to concentrate it to increase its density, adding a haloid of an alkali metal and beating the same while keeping it hot, allowing the syrup to partially cool and then adding a chlorid of the alkali earth metal group and agitating to bring the same into contact with the syrup to form precipitates, and then bleaching the resulting syrup.

12. The method of treating sulfite waste liquor fronrwood pulp mills, which consists in evaporatingthe waste liquor to concentrate it to about 20 to 30 per cent. of solids, then adding sodium chlorid while keeping ,hot, and beating, partially cooling the syrup to less than 150 Fahn, then adding a small percentage of barium chlorid and agitating the mixture to bring Said chlorid to form insoluble precipitates thereof, and then bleaching it.

13. The method of treating sulfite waste liquor from wood pulp mills, which consists in evaporating the waste liquor to about 20 to 30 per cent. of solids, then adding sodium chlorid while keeping hot, and beating, partially cooling the syrup to less than 150 Fahiz, and then adding a small percentage of barium chlorid and agitating to form insoluble precipitates thereof, and then drawing the syrup off from said precipitates.

ll. The method of treating sulfite waste liquor from wood pulp mills, which consists in partially evaporating said liquor, adding to said liquor sodium chlorid, then treating the resulting syrup with a chlorid of the alkali earth metal group to cause precipitation of certain of the spent chemical compounds in said liquor, and then drawing 0E the resulting substance from said precipitates and evaporating it. Y

15. The method of treating sulfite waste liquor from wood pulp mills, which consists in evaporating the waste liquor to about 20 to 30 per cent. of solids, then adding sodium chlorid while keeping the liquor hot, and beating said syrup until separation is evidenced, running said resulting mixture into a settling tank, and partly cooling the same, then adding a small percentage of barium chlorid as a precipitating agent, and then agitating the mixture to bring said chlorid into intimate contact with the mixture to form insoluble precipitates thereof, bleach ing the mixture, and then evaporating the same. I

16. The method of treating sulfite waste liquor from wood pulp mills, which consists in evaporating the waste liquor to about 20 to 30 per cent. of solids, then adding sodium chlorid while keeping hot, sufiicient to substantially neutralize the resulting syrup and beating, partially cooling the syrup to less than 150 Fahn, and then adding a small percentage of barium chlorid and agitating the mixture to bring said chlorid into intimate contact with the spent chemical compounds of the mixture to form insoluble precipitates thereof, then drawing 0E the resulting syrup from said precipitates, bleaching said syrup and evaporating the same down to an anhydrous mass, and reducing said mass to a powder.

17 An anhydrous composition of matter made from sulfite waste liquor by concentrating, treating the same with a haloid o'z' an alkali metal, precipitating by the use of barium chlorid the sulfur calcium compounds of the resulting mixture, and evaporating the mixture to a dry mass.

In testimony whereof I afiix, my signature, in the presence of two subscribing witnesses.

WALTER K. FREEMAN.

Witnesses:

JNo. S. GEORGE, CLARENCE W. House. 

